Magnetoelectronics devices incorporate ferromagnetic elements to perform specific functions, such as “latching” data, Boolean operations and similar functions. To detect a result of a Boolean operation, for example, magnetoelectronic devices typically utilize magnetic field sensors to detect the magnetic field induced by the ferromagnetic material.
Magnetic field sensors based on the Hall effect are presently the most widely used magnetic sensor. When a magnetic field is applied perpendicularly to an electric conductor, a voltage is generated transversely to a current flow direction in the electric conductor. This phenomenon is called the Hall effect and the voltage generated is called Hall voltage. Therefore, magnetoelectronic devices typically utilize a Hall sensor or element to sense the orientation of the magnetic field induced by a magnetic element.
Hall sensors are not only used for detecting a magnetic field. Hall sensors also provide signals that can be used for implementing various sensing and control functions. Discrete Hall sensors, coupled with current-excitation and signal-conditioning blocks, provide a voltage output in the presence of a magnetic field. A number of integrated circuit sensors ease the design task by combining Hall sensors and peripheral circuitry to provide linear or switched outputs. The majority of presently-available Hall sensors are low-cost discrete devices. The allure of contactless sensing, low parts cost, and easy design-in make Hall devices the sensors of choice in hundreds of automotive, aircraft, appliance, and tool applications.
Hall sensors may be integrated with semiconductor integrated circuits instead of employing discrete Hall sensor integrated circuits. Such integration allows a system approach thereby improving the sensor performance despite the mediocre characteristics of basic Hall cells.
It is desirable to provide integrated circuit devices with Hall sensors having higher sensitivity to simplify overall system designs, reduce cost, and decrease power consumption. Further, it is desirable to provide Hall sensors on reduced chip area, as compared with conventional processing, to allow for further scaling of devices. Also, it is desirable to facilitate the design and fabrication of Hall sensors over semiconductor-over-insulator (SOI) substrates. Also, it is desirable to provide methods for fabricating such integrated circuits that are cost effective and compatible with logic processing. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.